Imidazolium Dicarboxylate Based Metal-Organic Frameworks Obtained by Solvo-Ionothermal Reaction
Résumé
Solvo-ionothermal reactions were run between cobalt acetate or zinc acetate and 1,3-bis(carboxymethyl)imidazolium chloride ([(MimCO2H)2][Cl]). These reactions led to two isostructural metal–organic frameworks (MOFs). These two compounds, [(MimCO2)2]2Co and [(MimCO2)2]2Zn, were obtained as single crystals, and their structures were determined by single-crystal X-ray diffraction. These two analogs have a 2D framework consisting of the stacking of layers formed by interconnection of rings containing ligands and metal ions. The structural and thermal properties were analyzed by means of ancillary techniques encompassing FTIR, UV/Vis, NMR spectroscopy, and TGA/TDA measurements. In addition, magnetic and EPR spectroscopic measurements on [(MimCO2)2]2Co showed that the Co2+ ions are in a high-spin configuration with a large magnetic anisotropy relying on a rather unusual distorted tetrahedral coordination. The investigation of the optical properties revealed the photoluminescence of [(MimCO2)2]2Zn.